From 99e2c31484bba519925a65b442d0516fc6e01c94 Mon Sep 17 00:00:00 2001
From: Carlo Sala <carlosalag@protonmail.com>
Date: Wed, 18 Sep 2024 21:05:45 +0200
Subject: [PATCH] feat(git): add `git_previous_branch` function

Closes #12538
---
 lib/git.zsh | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/lib/git.zsh b/lib/git.zsh
index 2ad5afe04..8237af751 100644
--- a/lib/git.zsh
+++ b/lib/git.zsh
@@ -162,6 +162,18 @@ function git_current_branch() {
   echo ${ref#refs/heads/}
 }
 
+# Outputs the name of the previously checked out branch
+# Usage example: git pull origin $(git_current_branch)
+# rev-parse --symbolic-full-name @{-1} only prints if it is a branch
+function git_previous_branch() {
+  local ref
+  ref=$(__git_prompt_git rev-parse --quiet --symbolic-full-name @{-1} 2> /dev/null)
+  local ret=$?
+  if [[ $ret != 0 ]] || [[ -z $ref ]]; then
+    return  # no git repo or non-branch previous ref
+  fi
+  echo ${ref#refs/heads/}
+}
 
 # Gets the number of commits ahead from remote
 function git_commits_ahead() {